A high-density polyethylene prestressed concrete corrugated pipe and preparation method thereof

Abstract

The present invention relates to a high-density polyethylene corrugated pipe for prestressed concrete and a preparation method thereof, wherein the corrugated pipe comprises a plastic inner pipe, a plastic plate strip spirally wound and fixed on the plastic inner pipe, a pair of lap strips, a V-shaped buffer strip spirally wound on the plastic plate strip, a steel strip wrapped outside the buffer strip, and a corrugated strip coated outside the plastic plate strip and the steel strip; the preparation method comprises the following steps, firstly spirally winding a preform B on a preform A, and making the opening of the buffer strip face the lap strip, and then coating the outer surface of the plastic plate strip and the coating strip with an adhesive resin to obtain a corrugated pipe. The corrugated pipe of the present invention can effectively reduce the influence of vibration on it, so that the corrugated pipe has impact resistance and compressive strength; in addition, the method of the present invention can improve the stability of the corrugated pipe structure while reducing the processing steps, thereby ensuring the impact resistance of the corrugated pipe.

Description

Technical Field

[0001] The invention relates to the technical field of corrugated pipes, in particular to a high-density polyethylene corrugated pipe for prestressed concrete and a preparation method thereof. Background Art

[0002] Prestressed plastic corrugated pipes are used in post-tensioned prestressed concrete structures as perforated pipes for prestressed tendons. In post-tensioned prestressing technology, reserved channel technology is one of the key technologies. With the continuous advancement of materials, machinery, engineering and other technologies, reserved channels have evolved from the earliest extraction pipes to metal corrugated pipes, and then to the current plastic corrugated pipes. With the introduction of a series of infrastructure investment plans by the state, the construction of bridges and large venues is in full swing, which not only has a huge demand for prestressed concrete plastic corrugated pipes, but also puts forward more technical requirements for corrugated pipes.

[0003] A Chinese patent with authorization announcement number CN106090455A discloses a high-density polyethylene corrugated pipe, including: an inner corrugated pipe body and an outer corrugated pipe body, the inner wave crest of the inner corrugated pipe body and the outer wave crest of the outer corrugated pipe body are connected by an upper annular connecting block, the inner wave trough of the inner corrugated pipe body and the inner wave trough of the outer corrugated pipe body are connected by a lower annular connecting block, elastic foam is filled between the inner corrugated pipe body and the outer corrugated pipe body, and an annular semicircular protrusion is arranged on the inner side of the inner wave crest of the inner corrugated pipe body.

[0004] The above-mentioned existing technical solutions have the following defects: the above-mentioned high-density polyethylene corrugated pipe is mainly made of polyethylene pipe. Although the structural strength of the corrugated pipe is increased to a certain extent, for the working environment of the corrugated pipe for prestressed concrete, this corrugated pipe still has defects such as poor impact resistance and low compressive strength, which needs to be improved. Summary of the invention

[0005] In view of the shortcomings of the prior art, the first object of the present invention is to provide a high-density polyethylene prestressed concrete corrugated pipe, which has good impact resistance and compressive strength.

[0006] The second object of the present invention is to provide a method for preparing a high-density polyethylene prestressed concrete corrugated pipe, which has the advantages of simple steps and can ensure the impact resistance of the corrugated pipe.

[0007] To achieve the above first object, the present invention provides the following technical solutions:

[0008] A high-density polyethylene corrugated pipe for prestressed concrete comprises a plastic inner tube, a plastic plate strip spirally wound and fixed on the plastic inner tube, a pair of overlapping strips respectively arranged on both sides of the plastic plate strip and overlapping each other, a V-shaped buffer strip, a steel strip wrapped around the buffer strip, and a corrugated strip covering the plastic plate strip and the steel strip, wherein the buffer strip is spirally wound around the plastic plate strip in such a way that the V-shaped opening faces the pair of overlapping strips.

[0009] By adopting the above technical scheme, after the steel belt is installed on the plastic plate belt, through the shock-absorbing structure composed of the buffer belt and the steel belt, when an external force acts on the corrugated pipe, the above shock-absorbing structure can switch between two stable states, thereby storing mechanical energy in the buffer belt, and when the force in the opposite direction is applied to the corrugated pipe, the above shock-absorbing structure can be restored from the second stable state to the first stable state, thereby achieving the purpose of long-term impact resistance and pressure resistance; in addition, the steel belt supports the wave crest of the corrugated pipe, and is positioned on both sides by the buffer belt and the corrugated belt. Through the friction between the steel belt and the buffer belt and the corrugated belt, the mechanical energy absorption performance of the corrugated pipe can be further improved, thereby improving the impact resistance of the corrugated pipe; in this process, the plastic inner tube and the plastic plate belt are used as the base material, and then the buffer belt, the steel belt and the corrugated belt are installed along the overlap belt, which can effectively reduce the impact of vibration on the corrugated pipe, so that the corrugated pipe has impact resistance and pressure resistance.

[0010] Furthermore, the overlapping strip is respectively provided with an inner overlapping part and an outer overlapping part, the outer wall of the inner overlapping part is provided with a barbed groove, and the inner wall of the outer overlapping part is provided with a reverse barbed convex groove matched with the barbed groove. The friction between the overlapping parts can be increased by the mutually matched barbed groove and reverse barbed convex groove, which can ensure that the plastic plate strip is installed according to the predetermined pitch and prevent the plastic plate strip from moving easily after installation.

[0011] Furthermore, the buffer belt is composed of a flexible elastic body, and the surface of the buffer belt is evenly coated with a lubricating coating composed of lubricating oil. Due to the pre-tightening effect of the flexible elastic body itself, the friction coefficient between the buffer belt and the plastic plate belt and the steel belt is reduced by coating the lubricating oil, so that a better energy absorption effect can be achieved in a smaller volume, thereby improving the impact resistance and compressive strength of the corrugated pipe.

[0012] Furthermore, the outer wall of the buffer belt is provided with a pair of right-angle grooves, and a contact block that is in close contact with the steel belt is formed between the pair of right-angle grooves, and the contact surface between the contact block and the steel belt is set as an arc-shaped convex semicircular surface; the inner wall of the buffer belt is set as a step surface, and the step surface is set as an arc-shaped convex semicircular surface close to the circumferential side wall of the contact block. Guided by the semicircular surface, the buffer belt can be easily sleeved in the steel belt, and after installation, the point contact is changed to surface contact, and plastic deformation in the axial direction can be avoided; in addition, when the contact block is subjected to force, the step surface can cooperate with the contact block to buffer the force, so as to ensure the impact resistance of the corrugated pipe in a smaller volume.

[0013] Furthermore, the side edges of the steel strip are bent outwardly and formed into flanges, and a pair of bending strips are provided on the plastic strip, and the angle between the bending strip and the plastic strip is 15-75°; the pair of bending strips are buckled on the flanges on both sides of the steel strip, and the flanges are in contact with the surfaces of the plastic strip and the bending strip. From the cross-section, the bending strip and the steel strip with flanges are hooked together like a pair of hooks, so that the flanges on both sides of the steel strip can be pressed on the plastic strips in different sections, which is convenient for the installation of the steel strip.

[0014] Furthermore, the corrugated belt includes a covering belt wrapped around the steel belt and the bending belt, and an adhesive resin layer coated on the outer surface of the plastic plate belt and the covering belt, and the cross section of the adhesive resin layer is T-shaped. The adhesive resin layer is used to fill the gap between the plastic plate belt and the covering belt to make the surface of the corrugated pipe smooth and seamless.

[0015] To achieve the above second purpose, the present invention provides the following technical solutions:

[0016] A method for preparing a high-density polyethylene prestressed concrete corrugated pipe comprises the following steps:

[0017] S1 The high-density polyethylene masterbatch is extruded through a die, cooled and formed, and cut to length to obtain a plastic inner tube, a plastic plate strip with a bending portion and a lap strip, and a covering strip;

[0018] S2: firstly uniformly coating a layer of adhesive resin with a thickness of 0.1-0.2 mm on the surface of the plastic inner tube obtained in S1, then spirally winding and bonding the plastic strip to the plastic inner tube, and making the overlapping strips overlap each other to obtain a preform A;

[0019] S3: installing the buffer belt and the coating belt obtained in S1 on the inner and outer sides of the steel belt respectively to obtain a spiral preform B;

[0020] S4: First, the preform B obtained in S3 is spirally wound on the preform A obtained in S2, with the opening of the buffer belt facing the lap belt, and then the adhesive resin is coated on the outer surface of the plastic plate belt and the covering belt to obtain a corrugated tube.

[0021] By adopting the above technical scheme, the plastic plate strip is bonded and fixed to the plastic inner tube by adhesive resin, so that the preform A obtained has good structural strength. The installation gap between the preform A and the preform B is then sealed by adhesive resin, and the buffer belt and the steel belt can be installed in the direction with the opening facing the overlapping part. While reducing the processing steps, the stability of the corrugated pipe structure can be improved, thereby ensuring the impact resistance of the corrugated pipe.

[0022] Further, in the S1, 90-110 parts of recycled high-density polyethylene, 10-25 parts of mica powder, 2-4 parts of polyethylene wax and 1-3 parts of silane coupling agent that have been crushed and cleaned are pre-taken, put into a mixer and mixed for 12-14 minutes, the speed is 800-900r / min, and the temperature is 90-100°C; then 4-6 parts of gas-phase alumina, 2-5 parts of light stabilizer, 1-5 parts of antioxidant, and 10-25 parts of masterbatch are added in sequence, mixed for 18-20 minutes, the speed is 1000-1100r / min, and the temperature is 130-150°C; then the mixer is controlled to uniformly reduce the speed to 230-240 r / min within 1 minute, continue mixing for 2-3 minutes, and finally cool to 50-60°C, and extrude and granulate with a twin-screw extruder to obtain the high-density polyethylene masterbatch. The preparation of high-density polyethylene masterbatch is carried out in three stages. The first stage is the pre-mixing of main raw materials such as recycled high-density polyethylene and mica powder. The recycled high-density polyethylene and mica powder are combined through silane coupling agents, etc. to form a strong interfacial bonding force, thereby improving the tensile strength of the high-density polyethylene masterbatch; the second stage is the mixing of auxiliary agents such as gas-phase alumina and light stabilizers. Gas-phase alumina has a strong positive charge tendency, which is conducive to the formation of static electricity in high-density polyethylene masterbatch. Through the synergistic effect of gas-phase alumina, light stabilizers and antioxidants, the influence of light and oxygen on the corrugated pipe can be effectively controlled to avoid aging and brittleness of the corrugated pipe, thereby ensuring the impact resistance of the corrugated pipe.

[0023] Furthermore, the light stabilizer is a benzotriazole ultraviolet absorber, and the antioxidant is a metal ion passivator. The combination of the benzotriazole ultraviolet absorber and the metal ion passivator can prevent the migration and volatilization of additives such as gas-phase aluminum oxide and light stabilizer to the surface of the high-density polyethylene masterbatch product, and effectively improve the anti-aging performance of the corrugated pipe, thereby ensuring the impact resistance of the corrugated pipe.

[0024] Furthermore, the mica powder is 450-550 mesh flaky mica powder. The addition of mica powder of the above specifications can effectively increase the density of the corrugated pipe, and play the role of shielding ultraviolet rays and infrared rays, sound insulation and shock absorption, thereby ensuring the impact resistance of the corrugated pipe.

[0025] In summary, the beneficial technical effects of the present invention are:

[0026] The corrugated pipe of the present invention uses a plastic inner pipe and a plastic plate strip as a base material, and is then installed along the lap strip through a buffer strip, a steel strip and a corrugated strip, which can effectively reduce the impact of vibration on the corrugated pipe, and make the corrugated pipe have impact resistance and compressive strength;

[0027] The method of the present invention can improve the stability of the bellows structure while reducing the processing steps, thereby ensuring the impact resistance of the bellows. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the cross-sectional structure of the bellows of Example 1 of the present invention.

[0029] Figure 2 It is a schematic diagram of the connection relationship between the plastic inner tube, the plastic plate strip, the buffer strip, the steel strip and the corrugated strip in Example 1 of the present invention.

[0030] In the figure, 1. plastic inner tube; 2. plastic plate strip; 21. inner lap joint; 211. barbed groove; 22. outer lap joint; 221. reverse barbed convex groove; 23. bending strip; 3. buffer strip; 31. right-angle groove; 32. abutment block; 33. lubricating coating; 4. steel strip; 41. flange; 5. corrugated strip; 51. coating strip; 52. adhesive resin layer. DETAILED DESCRIPTION

[0031] In order to make the technical means, creative features, objectives and functions achieved by the present invention clearer and easier to understand, the present invention is further explained below in conjunction with the accompanying drawings and specific implementation methods.

[0032] Example 1: Reference Figure 1 , which is a high-density polyethylene corrugated pipe for prestressed concrete disclosed by the present invention, comprises a plastic inner pipe 1, a plastic plate belt 2, a buffer belt 3, a steel belt 4 and a corrugated belt 5 which are wrapped in sequence from the inside to the outside. The plastic plate belt 2 is bonded and fixed to the plastic inner pipe 1 in a spiral winding manner, and the buffer belt 3, the steel belt 4 and the corrugated belt 5 are all spirally installed on the plastic plate belt 2 in a manner that the center line is aligned with the winding seam of the plastic plate belt 2, so as to form a corrugated protrusion with shock-absorbing and pressure-resistant effects, so that the corrugated pipe has impact resistance and pressure resistance.

[0033] Reference Figure 2In the inner layer of the corrugated tube, an inner overlap portion 21 and an outer overlap portion 22 are respectively provided on both sides of the plastic strip 2. The outer wall of the inner overlap portion 21 is provided with a barb-shaped groove 211, and the inner wall of the outer overlap portion 22 is provided with a reverse barb-shaped convex groove 221 that matches the barb-shaped groove 211. After the plastic strip 2 is installed, the inner overlap portion 21 and the outer overlap portion 22 are overlapped together radially inside and outside. The friction between the overlap portions can be improved by the mutually matched barb-shaped groove 211 and the reverse barb-shaped convex groove 221, which can ensure that the plastic strip 2 is installed according to the predetermined pitch and prevent the plastic strip 2 from moving easily after installation.

[0034] The buffer band 3 is a key structure to ensure the impact resistance of the corrugated pipe, and its cross section is V-shaped. A pair of right-angle grooves 31 are provided on the V-shaped outer wall of the buffer band 3, and a contact block 32 is formed between the pair of right-angle grooves 31 to tightly contact the steel band 4, and the contact surface between the contact block 32 and the steel band 4 is set as an arc-shaped convex semicircular surface. The V-shaped inner wall of the buffer band 3 is set as a step surface, and the circumferential side wall of the step surface close to the contact block 32 is set as an arc-shaped convex semicircular surface. Guided by the semicircular surface, the buffer band 3 can be easily sleeved in the steel band 4, and after installation, the point contact is changed to surface contact, and plastic deformation in the axial direction can be avoided; in addition, when the contact block 32 is subjected to force, the step surface can cooperate with the contact block 32 to buffer the force, so as to ensure the impact resistance of the corrugated pipe in a smaller volume.

[0035] In order to further improve the impact resistance of the buffer belt 3, the buffer belt 3 is spirally wound on the plastic plate belt 2 in a manner that the V-shaped opening faces the pair of overlapping belts, and the buffer belt 3 is composed of a flexible elastic body, and its surface is evenly coated with a lubricating coating 33 composed of lubricating oil. Due to the pre-tightening effect of the flexible elastic body itself, the friction coefficient between the buffer belt 3 and the plastic plate belt 2 and the steel belt 4 is reduced by coating the lubricating oil, so that a better energy absorption effect can be achieved in a smaller volume, thereby improving the impact resistance and compressive strength of the corrugated pipe.

[0036] In the outermost layer of the corrugated pipe, the corrugated belt 5 is wrapped around the plastic plate belt 2 and the steel belt 4, and the steel belt 4 is wrapped around the buffer belt 3. The steel belt 4 is limited by the plastic plate belt 2 and can slide and detach along the plastic plate belt 2. The steel belt 4 supports the wave crest of the corrugated pipe, and the buffer belt 3 and the corrugated belt 5 are used to position it on both sides. The friction between the steel belt 4 and the buffer belt 3 and the corrugated belt 5 can further improve the mechanical energy absorption performance of the corrugated pipe, thereby improving the impact resistance of the corrugated pipe.

[0037] The specific connection method between the steel belt 4 and the plastic strip 2 is that the side of the steel belt 4 is bent outwardly and forms a flange 41, and a pair of bending belts 23 are provided on the plastic strip 2. The angle between the bending belt 23 and the plastic strip 2 is 15-75°, preferably 42° in this embodiment, and the pair of bending belts 23 are buckled on the flanges 41 on both sides of the steel belt 4 to force the flanges 41 to contact the surface of the plastic strip 2 and the bending belts 23. From the cross section, the bending belt 23 and the steel belt 4 with the flange 41 are hooked together like a pair of hooks, so that the flanges 41 on both sides of the steel belt 4 can be pressed on the plastic strip 2 in different sections, which is convenient for the installation of the steel belt 4.

[0038] In addition, the corrugated belt 5 includes a covering belt 51 wrapped around the steel belt 4 and the bending belt 23, and an adhesive resin layer 52 coated on the outer surface of the plastic plate belt 2 and the covering belt 51. The cross section of the adhesive resin layer 52 is T-shaped. The adhesive resin layer 52 is used to fill the gap between the plastic plate belt 2 and the covering belt 51, so that the surface of the corrugated pipe is smooth and seamless.

[0039] Correspondingly, the present invention also discloses a method for preparing the high-density polyethylene prestressed concrete corrugated pipe, comprising the following steps:

[0040] S1: 90 parts of recycled high-density polyethylene, 22 parts of mica powder, 3 parts of polyethylene wax and 2 parts of silane coupling agent that have been crushed and cleaned are pre-taken into a mixer and mixed for 13 minutes at a speed of 860 r / min and a temperature of 100°C; then 5 parts of fumed alumina, 4 parts of light stabilizer, 5 parts of antioxidant and 15 parts of masterbatch are sequentially added and mixed for 18 minutes at a speed of 1000 r / min and a temperature of 130°C; then the mixer is controlled to uniformly reduce its speed to 230 r / min within 1 minute, and the mixing is continued for 2 minutes, and finally cooled to 50°C, and extruded and granulated by a twin-screw extruder to obtain high-density polyethylene masterbatch;

[0041] The light stabilizer is a benzotriazole ultraviolet absorber, the antioxidant is a metal ion passivator, and the mica powder is a 450-550 mesh flaky mica powder;

[0042] S2 The high-density polyethylene masterbatch obtained in S1 is subjected to die extrusion, cooling and molding, and fixed-length cutting to obtain a plastic inner tube 1, a plastic plate strip 2 with a bending portion and a lap strip, and a covering strip 51;

[0043] S3: firstly, a layer of 0.1 mm thick adhesive resin is uniformly coated on the surface of the plastic inner tube 1 obtained in S2, and then the plastic plate strip 2 is spirally wound and bonded to the plastic inner tube 1, and the overlapping strips are overlapped with each other to obtain a preform A;

[0044] S4: The buffer belt 3 and the coating belt 51 obtained in S2 are respectively installed on the inner and outer sides of the steel belt 4 to obtain a spiral preform B;

[0045] S5: First, the preform B obtained in S4 is spirally wound on the preform A obtained in S3, and the opening of the buffer belt 3 is facing the overlapping belt, and then the adhesive resin is coated on the outer surface of the plastic plate belt 2 and the covering belt 51 to obtain a corrugated tube.

[0046] Embodiment 2: A method for preparing a high-density polyethylene prestressed concrete corrugated pipe disclosed in the present invention comprises the following steps:

[0047] S1: 93 parts of recycled high-density polyethylene, 25 parts of mica powder, 2 parts of polyethylene wax and 2 parts of silane coupling agent that have been crushed and cleaned are taken in advance, and put into a mixer for mixing for 12 minutes, with a speed of 830r / min and a temperature of 95°C; then 5 parts of fumed alumina, 2 parts of light stabilizer, 1 part of antioxidant and 10 parts of masterbatch are added in sequence, and mixed for 19 minutes, with a speed of 1050r / min and a temperature of 135°C; then the mixer is controlled to uniformly reduce the speed to 235r / min within 1 minute, and the mixing is continued for 2 minutes, and finally cooled to 55°C, and extruded and granulated by a twin-screw extruder to obtain high-density polyethylene masterbatch;

[0048] The light stabilizer is a benzotriazole ultraviolet absorber, the antioxidant is a metal ion passivator, and the mica powder is a 450-550 mesh flaky mica powder;

[0049] S2 The high-density polyethylene masterbatch obtained in S1 is subjected to die extrusion, cooling and molding, and fixed-length cutting to obtain a plastic inner tube 1, a plastic plate strip 2 with a bending portion and a lap strip, and a covering strip 51;

[0050] S3: firstly, a layer of 0.2 mm thick adhesive resin is uniformly coated on the surface of the plastic inner tube 1 obtained in S2, and then the plastic plate strip 2 is spirally wound and bonded to the plastic inner tube 1, and the overlapping strips are overlapped with each other to obtain a preform A;

[0051] S4: The buffer belt 3 and the coating belt 51 obtained in S2 are respectively installed on the inner and outer sides of the steel belt 4 to obtain a spiral preform B;

[0052] S5: First, the preform B obtained in S4 is spirally wound on the preform A obtained in S3, and the opening of the buffer belt 3 is facing the overlapping belt, and then the adhesive resin is coated on the outer surface of the plastic plate belt 2 and the covering belt 51 to obtain a corrugated tube.

[0053] Embodiment 3: A method for preparing a high-density polyethylene prestressed concrete corrugated pipe disclosed in the present invention comprises the following steps:

[0054] S1: 95 parts of recycled high-density polyethylene, 10 parts of mica powder, 4 parts of polyethylene wax and 1 part of silane coupling agent that have been crushed and cleaned are pre-taken, put into a mixer and mixed for 14 minutes at a speed of 825 r / min and a temperature of 93°C; then 6 parts of fumed alumina, 5 parts of light stabilizer, 3 parts of antioxidant and 20 parts of masterbatch are sequentially added and mixed for 20 minutes at a speed of 1100 r / min and a temperature of 140°C; then the mixer is controlled to uniformly reduce its speed to 240 r / min within 1 minute, and the mixing is continued for 3 minutes, and finally cooled to 50°C, and extruded and granulated by a twin-screw extruder to obtain high-density polyethylene masterbatch;

[0055] The light stabilizer is a benzotriazole ultraviolet absorber, the antioxidant is a metal ion passivator, and the mica powder is a 450-550 mesh flaky mica powder;

[0056] S2 The high-density polyethylene masterbatch obtained in S1 is subjected to die extrusion, cooling and molding, and fixed-length cutting to obtain a plastic inner tube 1, a plastic plate strip 2 with a bending portion and a lap strip, and a covering strip 51;

[0057] S3: firstly, a layer of 0.1 mm thick adhesive resin is uniformly coated on the surface of the plastic inner tube 1 obtained in S2, and then the plastic plate strip 2 is spirally wound and bonded to the plastic inner tube 1, and the overlapping strips are overlapped with each other to obtain a preform A;

[0058] S4: The buffer belt 3 and the coating belt 51 obtained in S2 are respectively installed on the inner and outer sides of the steel belt 4 to obtain a spiral preform B;

[0059] S5: First, the preform B obtained in S4 is spirally wound on the preform A obtained in S3, and the opening of the buffer belt 3 is facing the overlapping belt, and then the adhesive resin is coated on the outer surface of the plastic plate belt 2 and the covering belt 51 to obtain a corrugated tube.

[0060] Embodiment 4: A method for preparing a high-density polyethylene prestressed concrete corrugated pipe disclosed in the present invention comprises the following steps:

[0061] S1: 100 parts of recycled high-density polyethylene, 15 parts of mica powder, 4 parts of polyethylene wax and 3 parts of silane coupling agent that have been crushed and cleaned are taken in advance, put into a mixer and mixed for 13 minutes, the speed is 800r / min, and the temperature is 91°C; then 4 parts of gas-phase alumina, 3 parts of light stabilizer, 4 parts of antioxidant, and 25 parts of masterbatch are added in sequence, mixed for 20 minutes, the speed is 1050r / min, and the temperature is 145°C; then the speed of the mixer is controlled to decrease uniformly to 230 r / min within 1 minute, and the mixing is continued for 3 minutes, and finally cooled to 50°C, and extruded and granulated by a twin-screw extruder to obtain high-density polyethylene masterbatch;

[0062] The light stabilizer is a benzotriazole ultraviolet absorber, the antioxidant is a metal ion passivator, and the mica powder is a 450-550 mesh flaky mica powder;

[0063] S2 The high-density polyethylene masterbatch obtained in S1 is subjected to die extrusion, cooling and molding, and fixed-length cutting to obtain a plastic inner tube 1, a plastic plate strip 2 with a bending portion and a lap strip, and a covering strip 51;

[0064] S3: firstly, a layer of 0.2 mm thick adhesive resin is uniformly coated on the surface of the plastic inner tube 1 obtained in S2, and then the plastic plate strip 2 is spirally wound and bonded to the plastic inner tube 1, and the overlapping strips are overlapped with each other to obtain a preform A;

[0065] S4: The buffer belt 3 and the coating belt 51 obtained in S2 are respectively installed on the inner and outer sides of the steel belt 4 to obtain a spiral preform B;

[0066] S5: First, the preform B obtained in S4 is spirally wound on the preform A obtained in S3, and the opening of the buffer belt 3 is facing the overlapping belt, and then the adhesive resin is coated on the outer surface of the plastic plate belt 2 and the covering belt 51 to obtain a corrugated tube.

[0067] Embodiment 5: A method for preparing a high-density polyethylene prestressed concrete corrugated pipe disclosed in the present invention comprises the following steps:

[0068] S1: 110 parts of recycled high-density polyethylene, 18 parts of mica powder, 4 parts of polyethylene wax and 1 part of silane coupling agent that have been crushed and cleaned are taken in advance, put into a mixer and mixed for 13 minutes at a speed of 900 r / min and a temperature of 90°C; then 4 parts of fumed alumina, 5 parts of light stabilizer, 5 parts of antioxidant and 20 parts of masterbatch are added in sequence, mixed for 18 minutes at a speed of 1050 r / min and a temperature of 150°C; then the mixer is controlled to uniformly reduce its speed to 240 r / min within 1 minute, continue mixing for 2 minutes, and finally cool to 60°C, and extrude and granulate with a twin-screw extruder to obtain high-density polyethylene masterbatch;

[0069] The light stabilizer is a benzotriazole ultraviolet absorber, the antioxidant is a metal ion passivator, and the mica powder is a 450-550 mesh flaky mica powder;

[0070] S2 The high-density polyethylene masterbatch obtained in S1 is subjected to die extrusion, cooling and molding, and fixed-length cutting to obtain a plastic inner tube 1, a plastic plate strip 2 with a bending portion and a lap strip, and a covering strip 51;

[0071] S3: firstly, a layer of 0.1 mm thick adhesive resin is uniformly coated on the surface of the plastic inner tube 1 obtained in S2, and then the plastic plate strip 2 is spirally wound and bonded to the plastic inner tube 1, and the overlapping strips are overlapped with each other to obtain a preform A;

[0072] S4: The buffer belt 3 and the coating belt 51 obtained in S2 are respectively installed on the inner and outer sides of the steel belt 4 to obtain a spiral preform B;

[0073] S5: First, the preform B obtained in S4 is spirally wound on the preform A obtained in S3, and the opening of the buffer belt 3 is facing the overlapping belt, and then the adhesive resin is coated on the outer surface of the plastic plate belt 2 and the covering belt 51 to obtain a corrugated tube.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A high-density polyethylene prestressed concrete corrugated pipe, characterized in that: It comprises a plastic inner tube (1), a plastic strip (2) spirally wound and fixed on the plastic inner tube (1), a pair of overlapping strips respectively arranged on both sides of the plastic strip (2) and overlapping each other, a V-shaped buffer strip (3), a steel strip (4) wrapped around the outside of the buffer strip (3), and a corrugated strip (5) wrapped around the outside of the plastic strip (2) and the steel strip (4), wherein the buffer strip (3) is spirally wound on the plastic strip (2) in a manner such that the V-shaped opening faces the pair of overlapping strips; The outer wall of the buffer belt (3) is provided with a pair of right-angle grooves (31), and a contact block (32) that is in close contact with the steel belt (4) is formed between the pair of right-angle grooves (31), and the contact surface between the contact block (32) and the steel belt (4) is arranged as an arc-shaped convex semicircular surface; the inner wall of the buffer belt (3) is arranged as a step surface, and the circumferential side wall of the step surface close to the contact block (32) is arranged as an arc-shaped convex semicircular surface; The corrugated belt (5) comprises a covering belt (51) wrapped around the steel belt (4) and the bending belt (23), and an adhesive resin layer (52) coated on the outer surface of the plastic plate belt (2) and the covering belt (51), wherein the cross section of the adhesive resin layer (52) is T-shaped.

2. The high-density polyethylene prestressed concrete corrugated pipe according to claim 1, characterized in that: The overlapping belts are respectively arranged as an inner overlapping portion (21) and an outer overlapping portion (22); the outer wall of the inner overlapping portion (21) is provided with a barbed groove (211); and the inner wall of the outer overlapping portion (22) is provided with a reverse barbed convex groove (221) cooperating with the barbed groove (211).

3. The high-density polyethylene prestressed concrete corrugated pipe according to claim 1, characterized in that: The buffer belt (3) is composed of a flexible elastic body, and the surface of the buffer belt (3) is evenly coated with a lubricating coating (33) composed of lubricating oil.

4. The high-density polyethylene prestressed concrete corrugated pipe according to claim 1, characterized in that: The side edges of the steel belt (4) are bent outwardly and form flanges (41); a pair of bending belts (23) are provided on the plastic plate belt (2); the angle between the bending belts (23) and the plastic plate belt (2) is 15-75°; the pair of bending belts (23) are buckled on the flanges (41) on both sides of the steel belt (4), and the flanges (41) are in contact with the surfaces of the plastic plate belt (2) and the bending belts (23).

5. The method for preparing a high-density polyethylene prestressed concrete corrugated pipe according to any one of claims 1 to 4, characterized in that: The following steps are included: S1. Extruding high-density polyethylene masterbatch through a die, cooling and molding, and cutting to a fixed length to obtain a plastic inner tube (1), a plastic strip with a bending portion and a lap joint (2), and a covering strip (51); S2: firstly, a layer of adhesive resin with a thickness of 0.1-0.2 mm is uniformly coated on the surface of the plastic inner tube (1) obtained in S1, and then the plastic plate strip (2) is spirally wound and bonded to the plastic inner tube (1), and the overlapping strips are overlapped with each other to obtain a preform A; S3: installing the buffer belt (3) and the coating belt (51) obtained in S1 on the inner and outer sides of the steel belt (4) respectively, to obtain a spiral preform B; S4: First, the preform B obtained in S3 is spirally wound on the preform A obtained in S2, and the opening of the buffer belt (3) is facing the overlapping belt, and then the adhesive resin is coated on the outer surface of the plastic plate belt (2) and the covering belt (51) to obtain a corrugated tube.

6. The method for preparing a high-density polyethylene prestressed concrete corrugated pipe according to claim 5, characterized in that: In the S1, 90-110 parts of recycled high-density polyethylene, 10-25 parts of mica powder, 2-4 parts of polyethylene wax and 1-3 parts of silane coupling agent that have been crushed and cleaned are pre-taken, put into a mixer and mixed for 12-14 minutes, the speed is 800-900r / min, and the temperature is 90-100°C; then 4-6 parts of gas-phase alumina, 2-5 parts of light stabilizer, 1-5 parts of antioxidant, and 10-25 parts of masterbatch are added in sequence, mixed for 18-20 minutes, the speed is 1000-1100r / min, and the temperature is 130-150°C; then the mixer is controlled to uniformly reduce the speed to 230-240 r / min within 1 minute, continue mixing for 2-3 minutes, and finally cool to 50-60°C, and extrude and granulate with a twin-screw extruder to obtain the high-density polyethylene masterbatch.

7. The method for preparing a high-density polyethylene prestressed concrete corrugated pipe according to claim 6, characterized in that: The light stabilizer is a benzotriazole ultraviolet absorber, and the antioxidant is a metal ion passivator.

8. The method for preparing a high-density polyethylene prestressed concrete corrugated pipe according to claim 6, characterized in that: The mica powder is 450-550 mesh flaky mica powder.

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